Instead Mozilla has made the curious decision to pull the plug on the long-delayed project, while offering only small clues as to why the decision was made.

The announcement was posted by Mozilla Engineering Manager Benjamin Smedberg on the Bugzilla development page. He ordered Mozilla employees and community developers:

Please stop building windows 64 builds and tests.

As for why the he opted to pull the plug on 64-bit for now, he comments, "Many plugins are not available in 64-bit versions. The plugins that are available don’t work correctly in Firefox because we haven’t implemented things like windowproc hooking, which means that hangs are more common."

Firefox 64-bit development is dead for now. [Image Source: Flickr/dimnikolov]

Usually this is the result of a free plugin which does not properly clean up after itself.

In any event, if leaving a page open for 1 hour results in the use of more RAM you will probably benefit from finding the plugin which is leaking (Adobe or otherwise) and disable it.

Note: some change in memory usage is normal, like if ads are updated every 15 minutes, or you are watching a video. Simple, static pages should not have these issues, so if you are sitting at Google's home page and the memory usage keeps climbing then you have a problem which should be fixed.